Acid aftertreatment of metallized resorcinol-azo dyes further coupled on the fiber



Patented July 18, 1950 UNITED STATES PATENT- OFFICE;

ACID AFTERTREATMENT o ff MET iILIZE RESORCINOL-AZO DYES FURTHER oU- PLED ON THE FIBER Clemens Streck,- I)oudonville, N. Y., assignor to General Anilineda Film Corporation, New York,

N. Y., a corporation of Delaware a i No Drawing. Application December 7., 1948, Serial No. 64,045 b bath, and causing the diazo component to couple the coupling component on the fiber. One of the chief difficulties attendant upon such [a process the fact that man coupling componentsjare substantive to the oe'llulosic fiber and" hence, the concentration or the coupling component bath is progressively reduced as the coloring operation proceeds, resulting in a progressive decrease in the depth of the coloration. To maintain the coupling component concentration constant by progressive addition of supplemental coupling component to thebath is practically'impossible, so that the aforesaid procedure is unsuitable in practice when the coupling component is substantive to the material to be Substantivity toward cellulosici fiber (i. e. cotton and regenerated cellulose fiber or fabrics containing the same) is especially characteristic of coupling components suitable for the production of brown shades. However, the metallized o-carboxyand o-hydroxyaryl azo resorcinols disclosed as coupling components in U. S. P. 2,135,433, which yield brown shades on cellulosic textile materials when coupled thereon with diazotized aromatic amines, constituteian exception to this general rule. These coupling components have low substantivity toward "cellulosic materials, and when used in" a bath for impregnating material, reparatory to development with a diazo compo'u'nd thereon, the] concontra-non of the couplin component bath remains substantially unchanged. class of coupling components is therefore adapted in this respect for the production or uniform brown colors on cellulosic'materials innc'ontinubus dye ing and printing processes of the-typ described above.

Nevertheless, it" was; found; attempting to carry out continuous dyeing orcellulosic teiitile material by progressive -application'of the aforesaid coupling component ironijap -bathg and? subsequent development? 0E8: browni 'azoridyestuff on 3 Claims. (oils-4 i fiber by treatment with the coloration produced varied in different parts: of-the material from a reddish to a yellowish a diazonium salt, that shade of brown rendering the dyeing unacceptable. A similar variation'in shade resulted in printing cellulosic material grounded with' the aforesaid coupling component, with adiazonium compound made up in the form of a printing paste.- i v I have discovered that the aforesaid varia= tion in shade can be avoided in continuous dyeing orprinting processes employing said metallized o-carboXy and ohydroxyaryl azo resorciiiols for impregnating the material, by

bathing the material, after coupling is completed,

withanacid solution of sufliciently strong acidity to remove alkali metal bound by the dyestuff on the fiber. After removing the acid from the material, e. g. by rinsing with w'aterjthe goods" can besoaped, rinsed and dried, or otherwise finished in the usual manner. The colorations thus produced are brown shades of outstanding brilliance, having excellent fastness to light, washing'and similar deteriorating agencies, said colorations being uniform throughout the ma terial; The" metallized coupling components employed in accordance with my invention are metal complex compounds of o'-carboxyand o hydroxy aryl azo resorcinols, containing in complex combination, a metal having'an atomic Weight be-' tween 58 and 64 (i. e. copper, nickel or cobalt) and preferably copper, said coupling components containing no other acidic salt-forming substituent (e. g. COOH or SOs'I-I groups) in the aryl residue. formula X-MG*O wherein Ar is an aryl radical (of which the nuclei are preferably of the benzene, naphthalene or azo-benzene series), X is a radical in o-position The compounds have the general 3 siilf onamide groups (SO2NH2). The metallized aryl azo resorcinols of this invention are obtained by known methods, involving coupling a diazotized o-hydroxy, o-alkoxy or o-carboxy aromatic amine of the formula AINI-Iz (Ar having the samesignificance as in the formula given above) with resorcinol or a lower nuclear alkyl resorcinol, and subjecting the resulting azo compound in metallizing treatment, for example, by

heating in an aqueous solution or suspension;

of a complex-forming salt, oxide, hydroxide, or carbonate of a metal having an atomic weight of 58 to 64, preferably copper.

Diazonium compounds which are suitable for production of brown shades on cellulosic materials in accordance with my invention, when combined with the aforesaid coupling components, are diazotized aromatic amines contain 4 Example 1 7 grams of a coupling component having the following formula obtained by coppering a reaction product producedby coupling diazotized 2-amino-4-chlorophenol with resorcinol, are pasted with 14 cc. of alcohol, diluted with 15 cc. of cold water and .mixed with 3.5 cc. of 34 Be. sodium hydroxide solution. The resulting mixture is stirred into 1,000 cc. of water to which are added 10 cc. of

ing no acid salt-forming substituents in the the coupling components of the class above de-' scribed are dissolved in an aqueous alkaline solution (e. g. dilute caustic alkali solution such as aqueous sodium hydroxide). The textile material is impregnated with the coupling component solution by passing it through the bath and removing excess liquid, e. g. by passing itbetween squeeze-rolls. In order to dye the material, it is then passed through an aqueous solution of a diazonium salt having sufficient acidity to neutralize free alkali from the initial impregnating bath,

thereby promoting coupling of the diazonium. compound with the coupling component. Conpling occurs in neutral to weakly acid medium. In printing processes, the diazonium salt is made up in the form of a thickened aqueous printing paste which is printed on the material impregnated with the coupling component solution, the paste likewise having sufficient acidity to neutralize free alkali on the material and thereby effecting coupling in the printed areas.

In accordance with my invention, when coupling of the azo dye components on the material is complete, the dyed or printed goods is passed through an aqueous acid bath of sufliciently strong acidity to neutralize or remove all of the alkali metal bound by the azo dyestufi on the fiber. For this purpose, a strong acid bath is employed, preferably having a pH not greater than 2 and is preferably a dilute aqueous solution of a strong mineral acid, e. g. HCl, H2804, H3PO4. or an acid salt of strong mineral acid such as sodium bisulfate. Duration of the treatment is adjusted with regard to the particular conditions of agitation and concentration so as to insure thorough penetration of the material by the acid solution. In general, a period of less than 10 minutes is sufficient. The acid solution is then removed, for example, by rinsing with water or dilute alkali, and the goods are soaped, rinsed, and dried or otherwise finished in the usual manner.

The process of my invention is illustrated by the following examples wherein parts are "by weight unless otherwise indicated.

3 Be. sodium hydroxide solution and 10 cc. of Monopol oil (a soap of a, highly sulfonated unsaturated fatty acid of a natural fat or oil).

Cotton textile material is passed progressively through the resulting bath so as to impregnate it with the solution in a continuous manner. Excess impregnating solution is squeezed off, and the material is thereupon passed through an aqueous solution containing zinc chloride double salts of 5-ohloro-2-methoxy benzene diazonium chloride in a concentration of 1.075%. Coupling occurs spontaneously, the acid of the diazonium solution being sufficient to neutralize the free alkali of the coupling component solution carried by the fiber. In accordance with my invention, after the development of coloration is complete, the

material is passed through an aqueous 10 Be. hydrochloric acid solution, duration of the treat-'.

ment therewith being 3-5 minutes. After rinsing with water to remove the acid, the goods is soaped, rinsed and dried in the usual manner. The coloration thus produced is a uniform, rich yellowbrown shade having excellent fastness to ligh and Washing.

, Example 2 Cotton material impregnated with the coupling component solution as described in Example 1 is printed with an aqueous paste of the diazonium salt employed in the preceding example, made by replacing part of the water of the solution of Example 1 witha thickening agent such as British gum, dextrin, gum tragacanth or starch thickening to yield a printing paste of desired consistency. After development of the dyestuff on the fiber,

' the goods is passed through a hydrochloric acid bath and rinsed in the same manner described in the first example. Thereafter the goods can be soaped, rinsed and dried as indicated above. Brown printsare obtained of uniform shade having the outstanding fastness properties noted in the preceding example.

Instead of the couplingco'mponent employed in the foregoing examples, there can be substituted corresponding nickel or cobalt complex compounds of 5-chloro-2-hydroxyphenylazo resorcinol. Similarly, there can be used copper, nickel or cobalt complex compounds, but preferably the copper complex compounds, obtained by metallizing treatment of the following azo resorcinols:

4- (3'-su1fonamido -phenyl azo) -5 -methyl-2-hy-- droxyphenyl azo resorcinol 2-hydroxynaphthyl-1-azo resorcinol z-carboxyphenylazo resorcinol The resulting coppered complex compounds or the above listed materials have the following formulae Instead of the diazonium salts disclosed in the example, other diazonium salts can be substituted, as for example, the chlorides, acid sulfates, aryl sulfonates, and zinc chloride, cobalt chloride, magnesium chloride, or boron trifluoridediazonium chloride double salts derived from the following aromatic amines by diazotization and conversion to the aforesaid salts:

P,D-diamino diphenylamine 4-benzoylamino -2,5 -diethoxyaniline dianisidine 4-cyano-2,5-dimethoxyaniline p-amino-o,o'-azotoluene o-chloroaniline m-chloroaniline o-nitroaniline p-nitroaniline 2- (4' -chlorophenoxy) -5-chloroaniline 2,5-dichloroaniline 4-nitro-o-toluidine In carrying out the acid treatment of my invention, aqueous solutions of strong mineral acids such as sulfuric acid, hydrochloric acid, o-phosphoric acid, are preferably employed, for example, in concentrations up to about 20%, the amount of acid being preferably sufiicient to yield a pH of not more than 2; while excessive concentrations likely to injure the fiber or decompose the dyestuffs during acid treatment are avoided. After the treatment, the acid is removed as by rinsing, and the material is finished 70 2,135,433

in the usual manner as by soaping, rinsing and drying.

Instead of the cotton goods of the example, re generated cellulose textiles can also be dyed and printed in the same manner.

Variations and modifications which will be obvious to those skilled in the art can be made in the foregoing procedures without departing from the scope of the invention.

I claim:

1. In the process of coloring cellulosic material involving progressively impregnating the material by passage of the material through an aqueous alkaline solution of a coupling component of the class consisting of metal complex compounds of o-carboxy-and o-hydroxy aryl-azoresorcinols containing, in complex combination, a metal having an atomic weight between 58 and 64, said coupling component containing no other acidic salt-forming substituents, and developing an azo dye coloration for the impregnated material by applying thereto an aromatic diazonium salt containing no acidic salt-forming substituents, the improvement which comprises treating the material, after development of the azo dye coloration, with an acid solution having a, pH not greater than 2, in order to convert all of the alkali bound by the dyestuff to salts of said acid; and removing the acid from the material.

2. In the process of coloring cellulosic material involving progressively impregnating the material by passage of the material through an aqueous alkaline solution of a coupling component of the class consisting of a copper complex compound of o-carboxy and o-hydroxy aryl-azo-resorcinols, said coupling component containing no other acidic salt-forming substituents, and developing an azo dye coloration on the impregnated material by applying thereto an aromatic diazonium salt containing no acidic salt-forming substituents, the improvement which comprises bathing the material, after development of the azo dye coloration, with an aqueous solution of a strong mineral acid having a pH not greater than 2, in order to convert all of the alkali bound by the dyestuff to salts of said acid; and removing the acid from the material.

3. In a process of coloring a cellulosic material involving progressively impregnating the material by passage of the material through an aqueous alkaline solution of a complex copper compound of 5-chloro-2-hydroxyphenyl azo resorcinol, and developing an azo dye on the impregnated material by applying thereto an aromatic diazonium salt containing no acidic salt-forming substituents, the improvement which comprises bathing the material, after development of the azo dye colorations thereon, with an aqueous hydrochloric acid solution having a pH not greater than 2 in order to convert all of the alkali bound by the dyestuff to a salt of said acid, and rinsing the material to remove the acid.

. CLEMENS STRECK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Delis Nov. 1, 1938 Number 

1. IN THE PROCESS OF COLORING CELLULOSIC MATERIAL INVOLVING PROGRESSIVELY IMPREGNATING THE MATERIAL BY PASSAGE OF THE MATERIAL THROUGH AN AQUEOUS ALKALINE SOLUTION OF A COUPLING COMPONENT OF THE CLASS CONSISTING OF METAL COMPLEX COMPOUNDS OF O-CARBOXY AND O-HYDROXY ARYL-AZORESORCINOLS CONTAINING IN COMPLEX COMBINATION, A METAL HAVING AN ATOMIC WEIGHT BETWEEN 58 AND 64, SAID COUPLING COMPONENT CONTAINING NO OTHER ACIDIC SALT-FORMING SUBSITUENTS, AND DEVELOPING AN AZO DYE COLORATION FOR THE IMPREGNATED MATERIAL BY APPLYING THERETO AN AROMATIC DIAZONIUM SALT CONTAINING NO ACIDIC SALT-FORMING SUBSTITUENTS, THE IMPROVEMENT WHICH COMPRISES TREATING THE MATERIAL, AFTER DEVELOPMENT OF THE AZO DYE COLORATION, WITH AN ACID SOLUTION HAVING A PH NOT GREATER THAN 2, IN ORDER TO CONVERT ALL OF THE ALKALI BOUND BY THE DYESTUFF TO SALTS OF SAID ACID; AND REMOVING THE ACID FROM THE MATERIAL. 